The present invention relates generally to systems for the automation of laboratory tests, and particularly testing of biological specimens.
Laboratory testing has changed and improved remarkably over the past 70 years. Initially, tests or assays were performed manually, and generally utilized large quantities of serum, blood, or other biological fluids. However, as mechanical technology developed in the industrial workplace, similar technology was introduced into the clinical laboratory. With the introduction of new technology, methodologies were also improved resulting in improved quality of the results produced by the individual instruments, and a decrease in the amount of specimen required to perform each test.
Instruments have been developed to increase the efficiency of testing procedures by reducing turnaround time and decreasing the volumes necessary to perform various assays. Exemplary of such instruments are the Synchron™ line of automated analyzers available from Beckman Instruments of Fullerton, Calif. Such instruments are capable of automatically analyzing a large number of blood specimens and a large number of analytes, providing reliable, accurate, and fast analysis of specimens.
There remains room for improvement in the operations of clinical laboratories, in spite of the advances that have been made. For example, significant labor is still required for sample preparation. Sample preparation can include the sorting of specimens for processing, centrifugation, and removal of the caps of containers containing the specimens. Centrifugation requires loading multiple specimen containers, which are typically test tubes, into centrifuge buckets, balancing the weight of the buckets so the centrifuge is balanced, loading the buckets into the centrifuge, closing the centrifuge lid, centrifuging, opening the lid, removing the buckets, and then removing the test tubes from the buckets. All these operations are labor intensive, increasing the cost of laboratory analysis. Moreover, these labor intensive steps can lead to operator error. Also, human involvement always involves the risk of contamination of specimens by the operator, and exposure of the operator to dangerous biological substances.
There have been attempts to improve automation include the use of conveyor systems for conveying specimens to analyzers, such as those described in U.S. Pat. Nos. 5,178,834 and 5,209,903. A difficulty with using conveyor systems is that they generally are part of a total integrated system, which system includes special analyzers and other handling equipment. Thus a clinical laboratory that wishes to switch to a conveyor system may need to replace its entire existing system, with attendant high capital investment and significant training expense for the operators.
Another common problem in clinical laboratory systems is how to deal with “STAT” specimens. These are specimens that need immediate attention. For example, specimens from patients in the emergency room often require “STAT” analysis so attending physicians can determine the cause of the medical emergency. Present clinical systems currently depend on operator intervention to interrupt the normal flow of work to be certain that the STAT samples get immediate attention. However, in the hustle and bustle of a clinical laboratory these STAT samples and specimens do not always get the immediate attention they need.
Laboratory centrifuges of the prior art typically have a high-speed motor-driven spindle, a plurality of holders for test-tubes, test-tube racks and/or vials being provided at respective angularly spaced stations of a head assembly of the spindle, the head assembly being located within a tub-shaped cavity and surrounded by a safety ring, the centrifuge also having a safety-latched door for covering the cavity during operation of the spindle. The spindle is driven at a selected speed which can be as high as from about 3600 RPM up to about 100,000 RPM.
A number of challenges are associated with automation of centrifugation. For example:
1. It is desired to bypass centrifuging in some cases;
2. Access to the centrifuge is impeded by the presence of a protective cover, which typically swings vertically between open and closed positions;
3. Inordinate expense is associated with automating the cover and protecting against persons being injured during movement thereof;
4. It is necessary to have the centrifuge balanced within approximately 10 grams before high-speed operation can commence; and
5. Many processes are inordinately burdened by the time required for spinning the samples, particularly when lengthy periods are needed for loading and unloading the centrifuge, for programming spin cycles, and for accelerating and decelerating the centrifuge.
In some centrifuges of the prior art, a spindle head can be indexed to one of a plurality of rest positions for facilitating loading and unloading at corresponding angularly spaced receptacle stations of the spindle head assembly. However, these centrifuges are undesirably complex and expensive to provide in that separate motors and controls are used for the indexing and for high-speed operation; a further consequence being degraded high-speed performance resulting from added inertia that is associated with the indexing motor.
Accordingly, there is a need for a system that can automate the sample handling and sample preparation process, including the centrifugation for analytical procedures, including in particular, clinical laboratories. It is desirable that the system can be used with existing equipment, i.e., existing equipment does not need to be replaced, and can be used with a wide variety of existing analytical equipment. Further, system throughput should be only minimally affected by specimens requiring centrifugation. Moreover, it is desirable that the system recognize and expeditiously handle STAT samples, minimize the health risks associated with contacting biological samples, and minimize the chance that specimens will be inadvertently contaminated by operator error.